Replants | March 2017
One challenge of Virginia viticulture is winter damage and the resulting vine loss. The winter of 2014 was especially tough on young vines. In many cases the decline and eventual loss was agonizingly slow. We are still having to pull and replant a not-so-insignificant number of vines. Additionally between 2010 and 2012 we had vine losses up to 2% a year in our Chardonnay due to North American Grapevine Yellows. I mention this only because circumstances seem to have made me an unwilling vine replant expert. I would like to share some of my experiences.
Replant or Start Over
After the winter of 2014 it took me too long to make the decision to start over with some blocks rather than replant missing vines. Vineyard blocks four years old and younger took a big hit with anywhere from 20% to 60% vine loss. Unfortunately they didn’t all die right away. If fact we are still replanting, three years after the event. Merlot was particularly hard hit. We began to replant two blocks, but after the growing season of 2014 it became evident that vine death would continue. These two blocks are now Petit Verdot and Cabernet Franc. Other Merlot blocks faired well enough to continue with an aggressive replant program.
Over the past few years it has been difficult to estimate the number of replacement vines needed. In many cases vines that looked healthy did not bud out in the spring. I now order about 50% more replant vines than I think I need and then maintain a small nursery here at Hardscrabble. In May, after the replanting is complete, any extra vines are root pruned down to 1” in length and then planted in well-tilled soil at a shallow depth (all this for easier digging in the fall or spring).
All vines are dug up after one year. Any more than that and the roots are too extensive to use. The nursery is close to a water source (irrigation) and a vineyard block (ease of spraying when passing by with the tractor). Recently we have started to do some fall replanting only because we have time then. We use the vines from our own nursery, as they would be over wintering outside anyway.
The Stepchild Syndrome
Replants are destined to a tough life. They rarely get a chance at healthy, strong growth and are usually worked too hard too early resulting in consistently weak vines. Over the years I’ve developed a protocol to address this.
After harvest we dig out dead vines. This is more time consuming than the actual replanting, especially in older blocks. In March I walk each block and tag the location of the missing vines with surveyor’s tape. I prefer biodegradable tape, otherwise the vineyard starts looking like a realtor’s open house.
In our old vine blocks where the distance between vines is six feet, we replant two vines at four-foot spacing for vines on VSP and three vines at three-foot spacing for the remaining Lyre blocks (most of Hardscrabble’s Lyre has been removed). Asking a replant to fill in six feet of canopy on our soils won’t happen. If we have the time we will add some compost to each hole. Anything to give these vines a boost. They’ll need it.
The biggest challenge with replants is their very slow growth and our unintentional overcropping. Because of the competition from older siblings it takes two to four years longer for these vines to reach any kind of “cropable” maturity. The older the original vineyard, the longer replants take to get established.
The best way to address this is in pruning. Year after year these vines are cut back hard. Before any block is pruned, I walk it row by row and personally prune every replant. For the first three or four years the vine is headed back. No canes are tied down to the fruiting wire. I’ve observed a common scenario where a weak, young vine has two canes laid down and the vine is allowed to crop as if it were a mature vine. The vine quickly becomes exhausted and stunted. The vine is never able to reach maturity.
Even with aggressive pruning, young replants can easily become overcropped. Another one of my jobs is to walk the vineyard in June and remove clusters from replants. This is perhaps too time consuming (especially during our busiest vineyard month). I’ve been somewhat successful in training my staff to do this while leaf pulling, but multi-tasking in the vineyard is rarely 100% successful.
Eventually, with time and patience there will be a crop. This presents the next problem. Young vine grapes ripen as much as ten days earlier than old vines. When logistically feasible we pick the young vines ahead of the older vines. This is slow going. Often two or three of us will walk the vineyard with shoulder strap apple picking bags. These grapes are then combined with a younger block that we are picking that day.
In the 1980s and 1990s winters were consistently colder. Below zero Fahrenheit was common. Bud mortality was our great concern. Today the winters are warmer, but with widely fluctuating temperature swings. Vine response is expressed by vascular damage, graft union failure, crown gall, and vine death. This seems to be especially true with vines younger than five years old. We need to get a handle on how to address this problem, but in the meantime, managing replants will be a part of Virginia’s unique viticulture.